# -*- coding: utf-8 -*-
# Python 将列表中的指定位置的两个元素对调

# 定义一个列表，并将列表中的指定位置的两个元素对调。

# demo-1
def swapPositions(list, pos1, pos2):
    list[pos1], list[pos2] = list[pos2], list[pos1]
    return list

List = [23, 65, 19, 90]
print(List)
pos1, pos2 = 1, 3

print(swapPositions(List, pos1 - 1, pos2 - 1))

# demo-2
def swapPositions(list, pos1, pos2):
    first_els = list.pop(pos1)
    second_ele = list.pop(pos2 - 1)

    list.insert(pos1, second_ele)
    list.insert(pos2, first_els)

    return list

List = [23, 65, 19, 90]
print(List)
pos1, pos2 = 1, 3

print(swapPositions(List, pos1 - 1, pos2 - 1))

# demo-3
def swapPositions(list, pos1, pos2):
    get = list[pos1], list[pos2]
    list[pos2], list[pos1] = get
    return list

List = [23, 65, 19, 90]
print(List)
print(swapPositions(List, pos1 - 1, pos2 - 1))